The Pakistani Taliban are claiming credit for another attack, in the port city of Karachi. Just two days after at least 36 people died in a Taliban assault on Pakistan's Karachi airport, today's target is the headquarters of the Airport Security Force. NPR's Philip Reeves joins us now from Islamabad. Good morning.

PHILIP REEVES, BYLINE: Good morning.

MONTAGNE: And Phil, tell us what is happening, right now.

REEVES: Well, armed paramilitary forces are searching an area, close to the perimeter fence of the airfield at Karachi airport. And they're after a couple of militants, who, according to officials, came along this morning on a motorbike and opened fire on a base that belongs to the Air Force Community service. Now, that's the same force that took the brunt of Sunday's attack, when the Taliban stormed in, killing at least 11 of them.

This time, a couple of militants appeared to have tried to try to get in through a couple of entrances. We're told there was a fire fight and the militants fled. And now a military operation is underway to find them. We're looking at - we've been looking at TV pictures that show at least 11, probably many more, ambulances racing to the scene. The area does seem to be flooded by security forces, including paramilitary rangers, who came along in jeeps with mounted machine guns. And the armies being sent in, as a reinforcement.

MONTAGNE: Well, there was Sunday's attack on one of the terminals there, at the airport, now this attack against the Security Forces, themselves. Obviously, a message is being sent by the Taliban?

REEVES: Yes, it is. The Taliban said there would be more attacks. They appear to be fulfilling that threat. Once again, they've hit the Security Forces in the nation's biggest city, the economic turbine that drives Pakistan's economy. They've done it close by, the busiest airport in the country. You know, it's a further reminder that they have the capacity of to attack urban centers. And it's not just a question of carrying out attacks up in the mountains - in the distant mountains bordering Afghanistan, where they have their strongholds.

And it also shows that if it's true, as reports say, that their split, they can still carry out operations, two sophisticated operations - well, one very specific operation and another, in just two days. And finally, I think it reinforces the great body of evidence that they are well dug into the city of Karachi, where they control some neighborhoods. So if the government does, as many are calling on it to do, launch a small scale militia operation, in the mountains, they will have to do - they will run the big - the big risk of their being a response to that in the urban areas, particularly Karachi.

MONTAGNE: And just one thing, Phil. Just a few hours ago, Pakistani officials raised the death toll from Sunday's attack. Tell us why that death toll changed after two days.

REEVES: Well, these are cargo workers. And their bodies were recovered early today, after many hours. Many hours after Pakistani officials declared that the airport was clear after Sunday's attack. And flights had resumed and so on. Now the families of these missing workers have blocked the road leading to the airport saying that they were missing. And they wanted the authorities to find them. They'd received a cell phone message, from one of these workers, saying, they were trapped inside an area, close to a cold storage facility. And in the early hours today, local time, their bodies were finally retrieved, after rescue workers broke down some walls. And, according to provisional government ministers who've been talking about this, their bodies are so badly burned, that it will take several weeks to actually identify them.

MONTAGNE: That's NPR's Philip Reeves speaking to us from Islamabad about a second Taliban attack in as many days, on the Karachi airport. Phil, thanks very much.